Toothbrush



FIG. 1 is a right side elevational view of a toothbrush showing my new design, in the left side being a mirror image of the left side elevation view;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a top plan view thereof; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a toothbrush, as shown and described. 